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A174049
Prime numbers of the form x^2+y^2 such that Mobius(x) * Mobius(y) = 1.
2
2, 13, 29, 37, 53, 101, 173, 197, 293, 421, 541, 677, 709, 1021, 1069, 1117, 1373, 1381, 1429, 1597, 1621, 1669, 1709, 1741, 1789, 1861, 1901, 1933, 2053, 2213, 2269, 2293, 2341, 2381, 2557, 2677, 2749, 2797, 3061, 3109, 3221, 3613, 3637, 3701
OFFSET
1,1
REFERENCES
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 844.
LINKS
Jean-François Alcover, Table of n, a(n) for n = 1..1000
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
Marc Deléglise and Joël Rivat, Computing the summation of the Mobius function, Experiment. Math. 5:4 (1996), pp. 291-295.
EXAMPLE
2 is in the sequence because 2 = 1^2 + 1^2 and mobius(1)*mobius(1) = 1*1 = 1;
13 is a term because 13 = 2^2 + 3^2 and mobius(2)*mobius(3) = (-1)*(-1) = 1.
MAPLE
with(numtheory): T:=array(0..50000000): k:=1:for x from 1 to 1000 do: for y from x to 1000 do if mobius(x)* mobius(y)= 1 and isprime(x^2+y^2) then T[k]:=x^2+y^2:k:=k+1 fi od od: mini:=T[1]:ii:=1: for p from 1 to k-1 do for n from 1 to k-1 do if T[n] < mini then mini:= T[n]:ii:=n fi od: print(mini): T[ii]:= 99999999: ii:=1:mini:=T[1] :od:
MATHEMATICA
terms = 1000;
Reap[Do[p = x^2 + y^2; If[PrimeQ[p] && MoebiusMu[x] MoebiusMu[y] == 1, Sow[p]], {x, terms}, {y, x}]][[2, 1]] // Sort // Take[#, terms]& (* Jean-François Alcover, Aug 31 2020 *)
CROSSREFS
Cf. A008683.
Sequence in context: A041575 A042917 A366720 * A141336 A253970 A361836
KEYWORD
nonn
AUTHOR
Michel Lagneau, Mar 06 2010
EXTENSIONS
Corrected and edited by Michel Lagneau, Apr 25 2010
Typo in name and missing value inserted by D. S. McNeil, Nov 20 2010
STATUS
approved